Bell P-59 Airacomet

Last revised June 27, 2002

The Bell XP-59A Airacomet was America's first jet aircraft. For that
reason alone, the aircraft is of historic significance. Although it
never fired a shot in anger during World War II, it was nevertheless
important in that it provided a lot of important data on the care and
maintenance of jet aircraft, which proved invaluable when more
advanced jet fighters came in to service.

The history of the Airacomet is one of the most interesting of any of
the aircraft we have encountered so far in this series. For that, we
must go back a bit and start with the Bell XP-52.

The Bell XP-52 was an unorthodox fighter project that arose out of a
USAAC competition held in the winter of 1939 for a fighter that would
be much more effective than any extant--with a top speed, rate of
climb, maneuverability, armament, and pilot visibility, all of which
would be far superior to those of any existing fighter. In addition,
the fighter was required to have a low initial cost and had to be easy
and inexpensive to maintain.

The USAAC issued its requirements to the industry in the form of
Request for Data R-40C. No less than 50 responses came in. Among
these was the Model 16, which the Bell company had developed some
months earlier. Bell was famous for submitting unconventional
designs, and the Model 16 was no exception. It had a round,
barrel-shaped fuselage with the pilot seated in the nose and a 1250 hp
Continental XIV-1430-5 liquid-cooled twelve-cylinder inverted vee
engine mounted behind the pilot and driving a pair of contrarotating
coaxial propellers operating in pusher fashion. The wing was mounted
in mid-fuselage position, and was swept back at an angle of about 20
degrees. Twin booms were mounted about one-third of the way along the
wings outboard of the fuselage. The horizontal tailplane at the rear
connected the two booms. A tricycle landing gear was to be fitted,
with the nosewheel retracting into the fuselage and the mainwheels
retracting into the booms. Two 20-mm cannon were to be mounted in the
lower fuselage, and three 0.50-in machine guns were to be mounted in
the front of each of the twin booms.

One unusual feature of the Model 16 was the presence of an engine
radiator cooing air intake mounted in the extreme nose. Nose-mounted
air intakes were features which were later to be seen in jet-powered
fighters.

By the end of 1940, the Army purchasing commission had chosen six of
the submissions for further development. Among them was the Bell
Model 16. A single prototype was ordered under the designation XP-52.
However this order was canceled on November 25, 1941, before anything
could be built. It was replaced by an order for another Bell design,
based on the XP-52 but equipped with a more-powerful Pratt & Whitney
R-2800-52 air-cooled radial engine rated at 2000 hp and driving a pair
of three-bladed contrarotating pusher propellers. This aircraft was
assigned the designation XP-59 by the US Army. The XP-59 had
more-or-less the same unorthodox configuration as that of the XP-52,
complete with the unusual nose intake. Estimated maximum speed was
450 mph at 22,000 feet, and service ceiling was to have been 38,000
feet.

In the meantime, something happened in England which was to alter
radically the fate of the XP-59. In April of 1941, Major-General H.
H. Arnold paid a visit to Britain. While there, he was shown the
top-secret Gloster E-28/39 jet-powered aircraft, powered by one of
Wing Commander Frank Whittle's W2B centrifugal turbojets. Work on
jet-powered aircraft was well-advanced in Britain, and similar
projects were underway in both Germany and Italy. The USA was clearly
behind other major aircraft manufacturing nations in this
revolutionary new form of aircraft propulsion. General Arnold was so
impressed by the potentiality of this new technology that he
immediately asked if American engineers could be given the blueprints
of the new jet engine so that they could manufacture it under license
in the USA. Since the US government was being so generous with its
Lend-Lease aid to Britain, the RAF readily agreed.

On September 4, 1941, at a meeting at Wright Field, General Arnold
asked the General Electric Corporation of Schenectady, New York to act
as the prime American contractor for license production of the British
jet engine. General Electric was selected for this work because of
the company's extensive experience with turbines for various
industrial and aviation applications. Fifteen jet engines were
ordered. This work was to be carried out under the utmost secrecy.

The very next day, Bell Aircraft of Buffalo, New York was approached
and asked if it would build a fighter aircraft powered by the new
General Electric jet engines. The choice of Bell as prime contractor
for the manufacture of the first American jet fighter is sort of
curious. Some have suggested that Bell was chosen because, of all the
primary aircraft manufacturers in the USA, it had the least work to do
in building aircraft vital for the war effort. Others have suggested
that Bell was chosen because of its flair for imaginative design.
Still others claim that Bell was chosen by General Arnold for this
assignment primarily because of its proximity to the General Electric
plant, a primary concern if strict secrecy was to be maintained.
Perhaps all of these factors played a role.

Bell accepted the assignment, and agreed to build three aircraft.
They accepted a deadline to complete the first prototype eight months
after signing the contract on September 30, 1941. The serial numbers
of the three prototypes were to be 42-108784/108786.

In order to provide for strict secrecy, some rather extreme measures
were taken. In order to provide a cover, the Bell jet fighter project
was assigned the designation XP-59A. This was done in the hope that
even if Axis intelligence were to get wind of the XP-59A project, they
would mistakenly think that it was just an adaptation of the
totally-unrelated XP-59 piston-engined pusher fighter. At this time,
Bell engineers were already hard at work on the XP-59 pusher, but work
on this project was quietly abandoned in the next couple of months as
work on the jet fighter got under way. The XP-59 project was
officially cancelled on December 1, 1941.

The General Electric jet engine was assigned the cover designation
I-A, in the hope that enemy intelligence might mistake it for a new
turbosupercharger.

So the XP-59A and its jet engines were an early example of a "black"
project. Many more such "black" projects were to follow in later
years.

With the XP-59A project being given the highest priority, work
proceeded very rapidly. Since the General Electric jet engines were
being designed and built in parallel with the XP-59A, Bell engineers
had little or no knowledge about performance data of the engines, so
they adopted a fairly conservative design approach. Within two months
after the initial order, Bell engineers had submitted a design for a
fairly conventional aircraft, with a cantilever, laminar-flow,
mid-mounted wing and a fully-retractable tricycle landing gear. The
aircraft was fitted with two 1400 lb. st. General Electric I-A jet
engines, one mounted on either side of the fuselage under the wing
roots. The aircraft had a high tailplane, well out of the way of the
turbojet exhausts. It was fitted with a pressurized cockpit, still a
rather unusual feature for the time. Access to the cockpit was
through a side-hinged canopy. The fuselage was to be built in two
sections, the forward section comprising armament bay and cabin, and
the rear section being of stressed-skin semi-monocoque construction.
All control surfaces were fabric covered and manually-operated, the
ailerons being of the pressure-balance type with pressure seals. The
aircraft was fitted with aerodynamically-balanced, fabric-covered
flaps located inboard of the ailerons. Although the XP-59A was
primarily viewed as a test-bed for jet engines, the USAAF also viewed
it as a potential combat aircraft, and it was to carry a nose-mounted
armament of two 37-mm cannon with 44 rpg.

The USAAF approved the initial design, and construction of the three
prototypes got underway on January 9, 1942.

Without even waiting for the flight of the first XP-59A prototype, the
USAAF ordered thirteen service test YP-59As in March of 1942. Serial
numbers of the YP-59As were 42-108771/108783. These were to be
powered by improved versions of the General Electric engine, the I-16
(later designated J-31) rated at 1650 lb. st. each. They were to
have rearward-sliding cockpit canopies in place of the hinged canopies
of the prototypes.

The first XP-59A prototype was ready by the late summer of 1942, and
was ferried by rail out to Muroc Dry Lake, California (now Edwards
AFB) on September 12, 1942. Once it arrived in California, it was
fitted with a dummy propeller attached to its nose, just in case the
curious might see it and start asking why this aircraft didn't have a
propeller. On October 1, 1942, Bell's test pilot Robert Stanley was
undergoing some high-speed taxiing trials with the XP-59A when the
aircraft "inadvertently" became airborne for a short time. It made
its first official flight the next day, with a USAAF pilot at the
controls. This was remarkably rapid progress, the first flight of the
prototype taking place only 13 months after the contract had first
been awarded. The XP-59A weighted 7320 pounds empty and 12,562 pounds
maximum loaded. Wingspan was 45 feet 6 inches, length was 28 feet 2
inches, height was 12 feet 4 inches, and wing area was 386 square
feet.

As might be expected for such a revolutionary system of aircraft
propulsion, there were serious problems right from the start. The jet
engines were too heavy in relation to the amount of power they could
develop, and their exhaust was so hot that the turbine blades
regularly overheated and often broke off with catastrophic results.
The maximum speed was 404 mph at 25,000 feet, somewhat below
expectations. The engine installation was found to result in an
inordinate amount of aerodynamic interference, and the aircraft was
subject to severe directional snaking, making it a poor gun platform.
Nevertheless, work on the P-59 continued unabated, and remedies were
eventually found for its long list of faults.

The second XP-59A flew on February 15, 1943 and the third late in
April.

The first YP-59A reached Muroc in June of 1943, and the USAAF gave the
aircraft the name *Airacomet*. The first YP-59A flew in August of
1943. The YP-59A had more powerful 1650 lb. st. General Electric
I-16 (J31) turbojets. However, the YP-59A showed little improvement
in performance over the XP-59A. Empty weight increased to 7626
pounds, and maximum speed was a disappointing 409 mph at 35,000 feet.
Service ceiling was 43,200 feet. The last four YP-59As had a heavier
armament--three 0.50-inch machine guns and a single 37-mm cannon,
which had been standardized for the production P-59A.

The third YP-59A (Ser No 42-22611) was shipped to Britain in exchange
for the first production Gloster Meteor I. Upon arrival in England,
it was assembled by Gloster at Moreton Vallance, where it was flown
for the first time by a Bell test pilot on September 28, 1943. It was
assigned the RAF serial number of RJ362/G. It was transferred to the
Royal Aircraft Establishment at Farnborough on November 5, 1943. It
was on the top-secret Jet Flight list (along with the Gloster E.28/39,
the De Havilland Vampire, and the Gloster Meteor), but the Airacomet
was flown very little because of unserviceability and the lack of
spares. The RAF test pilots found the aircraft to be badly
underpowered, with an unacceptably-long takeoff run. Like all other
early jet-powered fighters, the Airacomet suffered from very poor
engine acceleration.

In December of 1943, the US Navy got the eighth and ninth YP-59As
(42-108778 and 42-100779) for use in tests. Some sources list their
naval designation as being YF2L-1, which is sort of curious since the
F2L designation was also used by a couple of Bell P-39Q Airacobras
employed by the Navy as target aircraft. Perhaps this inconsistency
was simply a part of the overall program of official deception, in the
hope that enemy intelligence would mistakenly think that the jets were
simply more naval Airacobras. In any case, the Airacomet was totally
unsuited for carrier operations because of the poor view from its
cockpit and the poor acceleration of its engines. In addition, the
Airacomet suffered from a lack of adequate drag during landing
approaches, so that there was a lot of "float" before touchdown when
the power was cut. The lack of drag was primarily caused by the
absence of dive brakes, which had been deliberately omitted because of
the Airacomet's anticipated mediocre performance.

The last YP-59A had been delivered by the end of June 1944.

Shortly before the first flight of the XP-59A, the USAAF had placed an
order for one hundred P-59A Airacomets. However, the performance of
the YP-59A service test aircraft had proved to be rather
disappointing, not even up to the standards of conventional
piston-engined fighter aircraft already in service with the USAAF. It
was considered rather unlikely that any appreciable improvements in
the performance of the P-59 would be soon be forthcoming, and by the
early fall of 1943 the Airacomet was no longer considered by the USAAF
as being worthy of consideration as an operational combat type. The
Airacomet was therefore relegated to the operational training role,
and the P-59A order was halved on October 30, 1943.

The production P-59A differed very little from the YP-59A. Only the
first twenty of the P-59A order were actually completed as P-59As.
Serials were 44-22609/22628. Most of these P-59As were powered by a
pair of 1650 lb. s.t. General Electric J31-GE-3 turbojets, although
the last few were powered by uprated 2000 lb. st. J31-GE-5 turbojets.
The J31-GE-5-powered P-59A had a maximum speed of 413 mph at 30,000
feet and 380 mph at 5000 feet. Range on internal fuel was 240 miles,
and range with two 125-Imp. gall. drop tanks was 520 miles. An
altitude of 10,000 feet could be reached in 3.2 minutes, and 20,000
feet in 7.4 minutes. Weights were 7950 pounds empty, 10,822 pounds
loaded, 12,700 pounds maximum. Dimensions were wingspan 45 feet 6
inches, length 38 feet 10 inches, height 12 feet 4 inches, and wing
area 385.8 square feet. Armament consisted of one 37-mm cannon and
three 0.50-inch machine guns, all mounted in the nose. In addition,
two 1000-pound bombs or eight 60-pound rockets could be carried on
underwing racks.

The twenty-first and remaining twenty-nine Airacomets of the P-59A
order were completed as P-59Bs. Serials were 44-22629/22658. They
had the uprated J31-GE-5 jets of the later P-59As, but had internal
fuel capacity increased by 55 Imp gall. Maximum range was increased
to 950 miles. Empty weight of the P-59B was increased to 8165 pounds
and normal and maximum loaded weights were 11,049 pounds and 13,700
pounds respectively. The last P-59B was delivered in May of 1945.

Most of the P-59s went to the 412th Fighter Group of the Fourth Air
Force based at Muroc Dry Lake (later Edwards AFB), where they served
in the training role. The Airacomets provided USAAF pilots and ground
crews with valuable data about the difficulties and pitfalls involved
in converting to jet aircraft. This information proved quite useful
when more advanced jet fighters finally became available in quantity.
A few P-59s were later modified and used as drone directors or manned
target aircraft aircraft with a second cockpit installed forward of
the main cockpit.

Although the Airacomet never saw service in its originally-intended
role as a fighter aircraft, it nevertheless provided the USAAF with
valuable orientation experience in the use of jet aircraft and
furnished a nucleus of trained jet pilots.

The Airacomet was to have one other major impact on aviation history,
one that is not generally recognized. Bell engineers undertook some
initial work on a single-engined version of the Airacomet, which was
designated XP-59B (not to be confused with the P-59B). It had a
low-mounted wing and was to be powered by a single General Electric
I-16 turbojet engine housed in the rear fuselage with an air inlet at
the wing roots and an exhaust in the tail. However, the Buffalo plant
was so busy with other projects that in late 1942 the USAAF
transferred the preliminary drawings of the single-engined XP-59B to
Lockheed, where it became the inspiration of the famed P-80 Shooting
Star.